30 Year Fixed Rate Mortgage
The traditional 30-year fixed-rate mortgage has a constant interest rate and monthly payments that never change. This may be a good choice if you plan to stay in your home for seven years or longer. If you plan to move within seven years, then adjustable-rate loans are usually cheaper. As a rule of thumb, it may be harder to qualify for fixed-rate loans than for adjustable rate loans. When interest rates are low, fixed-rate loans are generally not that much more expensive than adjustable-rate mortgages and may be a better deal in the long run, because you can lock in the rate for the life of your loan.

15 Year Fixed Rate Mortgage
This loan is fully amortized over a 15-year period and features constant monthly payments. It offers all the advantages of the 30-year loan, plus a lower interest rate—and you'll own your home twice as fast. The disadvantage is that, with a 15-year loan, you commit to a higher monthly payment. Many borrowers opt for a 30-year fixed-rate loan and voluntarily make larger payments that will pay off their loan in 15 years. This approach is often safer than committing to a higher monthly payment, since the difference in interest rates may not be that great.

3/1 ARM, 5/1 ARM, 7/1 ARM, 10/1 ARM
These increasingly popular ARMS — also called hybrid ARMs — can offer the best of both worlds: lower interest rates than "traditional" fixed rate loans but with a fixed rate for a temporary period of time. For example, a 5/1 ARM has a fixed rate and monthly principal and interest payment for the first five years and then adjusts annually after that.  It's a good choice for people who expect to move (or refinance) before or shortly after the adjustment occurs.